@dash267 I suspect there's quite a bit of difference due to the different mufflers and 1/4 wave pipes.

@Avera welp, that's a bummer, look forward to the next steps.

 

@dash267

Congrats on your exhaust setup. Glad you are enjoying what it has to offer.

I do not say this with even a hint of cynicism, but do not hold your breath on the audio. Aside from the fact that I have no way of uploading audio to this forum, there is NOTHING I have recorded that REMOTELY conveys what the setup sounds like in person.

Not sure you caught my last post, but I am replacing the Race Pipe with the OEM rear box. The tone was mind-blowing . . . but so was the drone.

As I said before, I do not think the Race Pipe alone is prone to unbearable drone and offers to be a great solution for anyone chasing an unparalleled, wailing tone. The problem resides with essentially having a straight pipe Dundon setup. Unlike the OEM rear box, the Race Pipe could not scavenge the drone.

With specific regard to the tone difference between my 70mm Race Pipe and the 63mm market option, all I can tell you is the tone is ear-splitting. LOUD AS H*LL! It WAILS. Is that because of the 70mm diameter alone, or because I have it coupled with the Dundon components? I suspect a little of both?

Unfortunately, I cannot tell you how the 70mm Race Pipe compares to the 63mm marketed option on their own? The only person who can is Jonny, given he tested the two of them. Once you throw in other aftermarket components (e.g., Dundon vs what you have), then things are hard to predict. All I can say is once you start shedding cats/resonators and dump the OEM rear box, you had better be prepared to deal with drone.

Enjoy your setup

Avera

 

Thank you @enduro . . . you and others have been a huge asset in my journey. I am very appreciative

Avera

 

Thank you for a reply @Avera ! My solution to drone was actually forcing the valve open. I also dealt with severe drone with just jcr oap and rear section. It was almost unbearable from 2500-3500rpm. However, the drone felt like it got better after installing headers and forcing the valve open with a module. Maybe it might be because I got used to the sound, but even now I get less annoyed by the drone with valved forced open during daily driving instead of keeping oem valve module.

 

@dash267

Very interesting you should state that about forcing the valves open . . .

I obviously reached my wits end with the drone. Desperate to try anything I considered whether - by some unexplicable miracle of the exhaust gods - holding the valves open could significantly attenuate the drone?

So, I ordered some 7mm valve shaft collars last week. I used collars on the OEM rear box which have 6mm diameter shafts vs 7mm shafts on the Race Pipe. The collars are due to arrive tomorrow and I have the local shop scheduled to replace the Race Pipe with the OEM rear box next week.

I will throw the valve shaft collars on when they arrive tomorrow, but have little-to-no expectation they will alter my scheduled course . . . if a miracle occurs I will be certain to report the event to the forum and the local diocese.

Avera

 

For anyone following this thread, you know the outcome . . . OEM rear box back in place

In MY opinion – given personal experience and reading the experiences of many others on this forum and thread – the 70mm Race Pipe would suit one of two owners:

1. Someone with Dundon headers/OAPs or similar aftermarket setup who predominantly/exclusively tracks their car.

In other words, someone who will spend most of their driving time above 4K RPM and has no decibel limit at frequented track(s) . . . or, I suppose, anyone who is ‘drone deaf’

2. Someone with stock headers/OAPs looking for that amazing JCR tone. I would anticipate a modest bump in decibels most likely coupled with a similarly modest bump in drone over the OEM rear box

Anyone who might be interested in the Race Pipe can PM me.

Avera

P.S. I am not going to continue to chase 'better' through other aftermarket rear box options. I do not think (1) anything produces the tone I am after other than JCR or (2) there is any aftermarket replacement for the OEM rear box that will not be associated with significant drone. The exception being the Akra slip-on and, possibly, SOUL slip on . . . but neither produce the tone I am after. So, I pushed the envelope and am willing to accept that Dundon headers/OAPs/OEM rear box is the best setup for ME. LOUD with valves open; minimal drone; TQ/HP gains . . . and a tone that I am willing to live with given the alternative explored and reported in this thread.

 

So, I wanted to share my views from the other side of the line I crossed

Driving with the OEM rear box replaced today was actually like the first drive after taking delivery of my GT4

I knew the drone was horrific, but did not fully appreciate how horrific it actually was until I had the OEM rear box replaced . . . damn, I REALLY crossed a line chasing 'better'

The Dundon components with OEM rear box is my 'Goldilocks.' Purrs like a kitten with valves closed. Roars like a lion with valves open. Tone is not nearly as bad as I once thought . . . that is me acknowledging the enemy of good is better

Avera

 

In your entire venture, did you have the chance to hear in person the Cargraphic X-Pipe + Flow-optimized OAP? This is what I run in my Spyder and you would have to pay me to come back to stock.

 

@IRM As you know, the number of aftermarket options, and combinations therein, are seemingly endless. So, like most, I have had to rely on the experiences of others to hear many of the options available through online discussion and video/audio. Although less than ideal, such approach is the only realistic way to gain reasonable impressions and has proven relatively effective.

With specific regard to the Cargraphic X-Pipe and OAP, it was never a consideration on my end. First, the Dundon headers/OAPs are a mutually inclusive setup. Second, as I have stated previously, the Dundon components are non-negotiable on my end. Third, I have yet to come across anyone with Dundon headers/OAPs combined with Cargraphic X-Pipe.

I am not surprised you like your setup, and happy to hear that you do. Again, so many aftermarket options and seemingly satisfied customers out there.

As for me, and as indicated at thread outset, my JCR Race Pipe pursuit was based primarily upon one thing: JCR Tone. Delivered tone in spades, but the drone price was too high.

So, overall, I am more than content with my current setup. It’s not perfect, but it’s as close as I’m going to get toward what I am after.

Avera